Key Takeaways Zacks highlights five mid-cap fintech stocks poised for long-term gains amid digital finance growth. BILL, ACIW, FOUR, OPFI and STNE have shown rising earnings estimates and expanding client bases. Sector momentum is driven by AI adoption, mobile banking growth, and real-time payment innovations.Financial technology (fintech) represents a transformative investment space in a hybrid sector merging finance and technology. The companies featured in the space offer a variety of services, such as ...